With the wolfSSL backend, when CA caching is enabled and an `CURLOPT_SSL_CTX_FUNCTION` callback...

With the wolfSSL backend, when CA caching is enabled and an CURLOPT_SSL_CTX_FUNCTION callback replaces the trust store, libcurl can silently reinstall the cached store after the callback returns. A certificate trusted by the cached store but rejected by the callback-selected store is then incorrectly accepted.